<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
  <link rel="stylesheet" href="./css/index.css">
</head>

<body>

  <ul class="wrap">
    <li id="pic1"><img class="Picture" src="images/pic1.jpg" alt="图片1" />
      <a href="#pic4" class="left">
        <img src="images/pic4.jpg" />
      </a>
      <a href="#pic2" class="right">
        <img class="right" src="images/pic2.jpg">
      </a>
    </li>
    <li id="pic2"><img class="Picture" src="images/pic2.jpg" alt="图片2" />
      <a href="#pic1" class="left">
        <img src="images/pic1.jpg" />
      </a>
      <a href="#pic3" class="right">
        <img class="right" src="images/pic3.jpg">
      </a>
    </li>
    <li id="pic3"><img class="Picture" src="images/pic3.jpg" alt="图片3" />
      <a href="#pic2" class="left">
        <img class="right" src="images/pic2.jpg">
      </a>
      <a href="#pic4" class="right">
        <img class="right" src="images/pic4.jpg">
      </a>
    </li>
    <li id="pic4"><img class="Picture" src="images/pic4.jpg" alt="图片4" />
      <a href="#pic3" class="left">
        <img class="right" src="images/pic3.jpg">
      </a>
      <a href="#pic1" class="right">
        <img class="right" src="images/pic1.jpg">
      </a>
    </li>
  </ul>

</body>

</html>